“Bullet time,” also known as “time slice” and “time freeze,” is a visual effect of stopped time or slowed time. Bullet time is famous for being used in the movie series “the Matrix” to feature, for example, actors dodging bullets, and received its time because of these scenes. Bullet time is characterized both by its extreme transformation of time (slow enough to show normally imperceptible events, such as flying bullets) and space (by way of the ability of the camera angle, i.e., the audience's point-of-view, to move around the scene at a normal speed while events are slowed). Bullet time has been widely utilized in movies, commercials, video games, sports broadcasting, music videos, etc.
Bullet time can be achieved using a series of cameras, such as a camera array consisting of 25-150 cameras, surrounding the filmed subject. When the subject starts to make an action, the cameras are fired sequentially, or all at the same time, depending on the desired effect. The frames generated by each camera are then arranged and displayed consecutively to produce an orbiting viewpoint of an action frozen in time or in slow motion.
Despite all the fascination it has excited, bullet time is expensive and time-consuming to create. A typical bullet-time setup requires multiple cameras accurately lined up on a carefully designed rig. Both building the rig and installing the cameras can be daunting tasks. Moreover, a lot of efforts need to be spent on interpolating frames (i.e., creating frames between frames) using a special software program to achieve the final effect. Therefore, “the Matrix” type of bullet time is teamwork by at least a software engineer, an imbedded-system engineer, photography director, a rig installation crew, and other assistants. The production periods may last from 24 hours to several weeks and the production cost can easily exceed 1 million dollars.
The disclosed methods and systems address one or more of the problems listed above.